Antibodies Unrelated to Epstein-Barr Virus in Human Sera Which Precipitate Soluble Components of Cultured Lymphoblasts2

Abstract

In immunodiffusion tests with extracts of cultured human Iymphoblasts and human sera, two lines of precipitation were obtained that clearly were unrelated to Epstein-Barr virus (EBV). All 96 human sera without antibodies to EBY tested produced at least one line, and many both of these lines, as did sera from several animal species. The corresponding antigens were present not only in Iymphoblasts harboring Epstein-Barr viral DNA but also in blastoid cells free of EBYgenomes as well as in extracts of peripheral and cord-blood leukocytes. The serum activity was found among the -γ-globulins and concentrated in the IgG fraction. While the antigens remained unidentified, they were evidently unrelated to fetal calf serum present in the culture media. The development of the precipitates wasenhanced by incorporation of dextran into the agarose. Sera with high titers of antibodies to EBY-related antigens gave generally heavier precipitates and could be used in higher dilutions than sera without such antibodies, and they produced one or two additional, presumably EBYspecific, lines of precipitation.